DOMESTIC AND FOREIGN INCOME TAXES (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Domestic and foreign components of income from continuing operations before domestic and foreign income taxes
Income from continuing operations before income taxes, Domestic	$ (732,000,000)	$ 3,399,000,000	$ 852,000,000
Income from continuing operations before income taxes, Foreign	2,273,000,000	4,747,000,000	5,636,000,000
Income from continuing operations before income taxes, Total	1,541,000,000	8,146,000,000	6,488,000,000
Provisions (credits) for domestic and foreign income taxes on continuing operations
Current United States Federal tax expense (benefit)	870,000,000us-gaap_CurrentFederalTaxExpenseBenefit	113,000,000us-gaap_CurrentFederalTaxExpenseBenefit	(308,000,000)us-gaap_CurrentFederalTaxExpenseBenefit
Current State and Local tax expense (benefit)	81,000,000	17,000,000	4,000,000
Current Foreign tax expense (benefit)	1,912,000,000us-gaap_CurrentForeignTaxExpenseBenefit	2,170,000,000us-gaap_CurrentForeignTaxExpenseBenefit	2,383,000,000us-gaap_CurrentForeignTaxExpenseBenefit
Current Total tax expense (benefit)	2,863,000,000us-gaap_CurrentIncomeTaxExpenseBenefit	2,300,000,000us-gaap_CurrentIncomeTaxExpenseBenefit	2,079,000,000us-gaap_CurrentIncomeTaxExpenseBenefit
Deferred United States Federal tax expense (benefit)	(1,037,000,000)	883,000,000	519,000,000
Deferred State and Local tax expense (benefit)	(71,000,000)	48,000,000	20,000,000
Deferred Foreign tax expense (benefit)	(70,000,000)	(17,000,000)	41,000,000
Deferred Total tax expense (benefit)	(1,178,000,000)us-gaap_DeferredIncomeTaxExpenseBenefit	914,000,000us-gaap_DeferredIncomeTaxExpenseBenefit	580,000,000us-gaap_DeferredIncomeTaxExpenseBenefit
United States Federal Total tax expense (benefit)	(167,000,000)	996,000,000	211,000,000
State and Local Total tax expense (benefit)	10,000,000	65,000,000	24,000,000
Foreign Total tax expense (benefit)	1,842,000,000	2,153,000,000	2,424,000,000
Total tax expense (benefit)	1,685,000,000us-gaap_IncomeTaxExpenseBenefit	3,214,000,000us-gaap_IncomeTaxExpenseBenefit	2,659,000,000us-gaap_IncomeTaxExpenseBenefit
Reconciliation of the United States federal statutory income tax rate to Occidental's worldwide effective tax rate on income from continuing operations
United States federal statutory tax rate (as a percent)	35.00%	35.00%	35.00%
Effect of spin-off of California Resources	12.00%
Operations outside the United States (as a percent)	65.00%	5.00%	6.00%
State income taxes, net of federal benefit (as a percent)	1.00%	1.00%	1.00%
Other (as a percent)	(4.00%)	(1.00%)	(1.00%)
Worldwide effective tax rate (as a percent)	109.00%	40.00%	41.00%
Deferred Tax Assets and Liabilities
Deferred Tax Assets, environmental reserves	123,000,000	121,000,000
Deferred Tax Assets, postretirement benefit accruals	379,000,000	376,000,000
Deferred Tax Assets, deferred compensation and benefits	208,000,000	222,000,000
Deferred Tax Assets, asset retirement obligations	307,000,000	407,000,000
Deferred Tax Assets, foreign tax credit carryforwards	1,765,000,000	1,091,000,000
Deferred tax Assets, federal benefit of state income taxes	85,000,000	136,000,000
Deferred Tax Assets, all other	274,000,000us-gaap_DeferredTaxAssetsOther	344,000,000us-gaap_DeferredTaxAssetsOther
Deferred Tax Assets, subtotal	3,141,000,000us-gaap_DeferredTaxAssetsGross	2,697,000,000us-gaap_DeferredTaxAssetsGross
Deferred Tax Assets, valuation allowance	(1,744,000,000)	(1,074,000,000)
Deferred Tax Assets, total deferred taxes	1,397,000,000us-gaap_DeferredTaxAssetsNet	1,623,000,000us-gaap_DeferredTaxAssetsNet
Deferred Tax Liabilities, property, plant and equipment differences	4,081,000,000	8,363,000,000
Deferred Tax Liabilities, equity investments, partnerships and foreign subsidiaries		225,000,000
Deferred Tax Liabilities, all other	221,000,000us-gaap_DeferredTaxLiabilitiesOther	82,000,000us-gaap_DeferredTaxLiabilitiesOther
Deferred Tax Liabilities, Gross	4,302,000,000us-gaap_DeferredIncomeTaxLiabilities	8,670,000,000us-gaap_DeferredIncomeTaxLiabilities
Deferred Tax Liabilities, total deferred taxes	4,302,000,000us-gaap_DeferredTaxLiabilities	8,670,000,000us-gaap_DeferredTaxLiabilities
Deferred tax assets, current	110,000,000us-gaap_DeferredTaxAssetsNetCurrent	150,000,000us-gaap_DeferredTaxAssetsNetCurrent
Unremitted earnings of certain consolidated foreign subsidiaries	9,900,000,000oxy_UnremittedForeignEarnings
Deferred tax liability not recognized, indefinitely reinvested foreign earnings	140,000,000
Discontinued operations income tax charges (benefits)	454,000,000	550,000,000	466,000,000
Credit to additional paid-in capital, excess tax benefit from the exercise of certain stock-based compensation awards	4,000,000	6,000,000	8,000,000
Unrecognized tax benefits included in deferred credits and other liabilities - other that would affect effective tax rate	61,000,000
Reconciliation of unrecognized tax benefits
Balance, at beginning of period	61,000,000us-gaap_UnrecognizedTaxBenefits	76,000,000us-gaap_UnrecognizedTaxBenefits
Reductions based on tax positions related to prior years and settlements		(15,000,000)
Balance, at end of period	$ 61,000,000us-gaap_UnrecognizedTaxBenefits	$ 61,000,000us-gaap_UnrecognizedTaxBenefits	$ 76,000,000us-gaap_UnrecognizedTaxBenefits

The tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from currently non-deductible expenses in environmental reserves, which can only be deducted for tax purposes when such liabilities are actually incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken.

No definition available.